Gamma ferric oxide hydrate and method of making same



Patented Jan. 17, 1933 PATENT) OFFICE am naumscu, or mrnasnoar, czacxosnovaxn.

Gm IMO OXIDE HYD BATE AND IEIHOD 0] IAKING am 1'0 Drawing. Application filed September 18, 1829,

This invention relates to a new roduct, chemically pure fabric oxide ydrate (Fe O H O) of the gamma configuration,

and to a method of making the same.

It has long been known that two minerals, othite and lepidocrocite, contain iron in the orm Fe O H O, but differ in their crystalline form and in the fact that, when dehydrated by heating at a moderate temperature, lepidocrocite becomes ferroma etic, while gothite does not. Since lepi ocrocite has alwa s been found to contain manganese oxide, it was thought that the presence of this impurity was the cause of the difference between its properties and those of gothite; but W. H. Albrecht (Ber. d. Deutschen Chem. Gas. 62, 147 5, 1929) has shown that gothite and lepidocrocite have different X-ray spectrums. Albrecht also showed that there existed a hydrate free from manganese having the X-ray spectrum of lepidocrocite and possessin the same ferromagnetic qualities when de ydrated. This hydrate has been termed the gamma form to distinguish it from the alpha form of ferric oxide hydrate which occurs in othite. Albrecht did not find any method. y which gamma hydrate could be made with certainty, nor was he able to prepare it in pure form. I have invented a method by which the gamma ferric oxide hyrate Fe.0.H.0) is for the first time produced with certainty and in chemically pure form. The niethod is simple and can easily be practiced commercially. The produEt has valuable therapieutic properties and is also useful as a cata st. v

The method consists in dissolving chemically pure iron in pure hydrochloric acid, and adding to the solution an excess of a non-metallic water-soluble base taken from the following class: pyridine, aniline, and similar ring compounds containing nitrogen, and passing air or oxygen through the solution. This results in the precipitation of chemically pure gamma Fe O H O.

I cite the following as a specific example of my method:

Chemically pure iron prepared by known methods from ferro-pentacarbonyl is dis- Serlal Ho. 398,587, and in Germany Icy 17, was.

solved in a solution of pure h drochloric acid of a concentration of from li ve to thirty-five per cent to form a ferrous chlorine solution whlch is neutral to Congo paper. An excess of pyridine or aniline is added to the solution, and air is assedthrough the solution, causing a precipitation of gamma Fe,,o.H.0.

The product has a crystalline structure and X-ray spectrum similar to those of lepidocrocite, becomes ferroma netic on dehydration, and is entirely free om manganese and all other metallic impurities.

What I claim is:

I. A process for reparing gamma ferric f oxlde hydrate, whic consists 1n preci itatin the same from a pure ferrous c oride so utlonwlth an organic base selected from the group consistingof pyridine and aniline in the presence of oxygen.

2. A process for preparing gamma ferric oxide hydrate, which consists in dissolvin pure iron in a solution of hydrochloric aci adding to the solution an organic base selected from the group consisting of pyridine and aniline, and passing oxygen through the solu- 5 tion to cause a precipitation.

3. A process for preparing gamma ferric oxide hydrate, which consists in dissolving pure iron in a solution of hydrochloric acid,

adding pyridine to the solution, and passing oxygen through the solution to cause a precipitation.

4. A process for preparing gamma ferric oxide hydrate,'which consists in dissolvin pure iron obtained from ferro-pentacarbony in a solution of hydrochloric acid until the solution becomes neutral to Congo paper, adding to the solution an organic base selected from the group consisting of pyridine and aniline, and passing oxygen through the solution to cause precipitation.

5. Chemidally pure gamma ferric oxide hydrate adapted for therapeutic uses precipitated from a pure ferrous chloride solutlon by an organic base selected from the group consisting of pyridine and aniline, in the presence of oxygen.

In testimony whereof I have hereunto set m hand.

y OSKAR BAUDISCH.

CERTIFICATE OF CORRECTION.

Patent No. 1,894,749 January 17, 1933.

OSKARV BAUDISCH.

'It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 2, for "fabric" read "ferric", and line 53, for "chlorine" read "chloride"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office. Signed and sealed this 28th day of February, A. D. 1933.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

